Try a clean reinstall of the game and patch. Uninstall the game, reboot, delete the 'Divinity 2' game folder if it still remains (saves are in a different locations) as well as the 'Profile' folder (see below), install the game, reboot (optional), and install the patch.
The unlocker program is a utility to delete files that Windows will not let you (or a program's uninstall) delete normally, because some program has it marked as being in use, or Windows thinks it does. If you have a problem clearing out the game files after uninstalling, booting into Safe Mode will usually allow you to delete any corrupt files (hold F5 down on Windows start, or F8 for a boot menu, IIRC).
In Vista / Win 7 the graphics configuration file, at least, is in the folder below (I have the Xbox version).
C:\Users\ %username% \AppData\Local\Divinity 2\Profile
or in XP
C:\Documents and Settings\ %username% \Local Settings\Application Data\Divinity 2\Profile
You may need to set Windows Explorer to show hidden files and folders.